The present invention generally relates to semiconductor devices, and more particularly, to through-silicon-via (TSV) structures located within such semiconductor devices.
TSVs may, among other things, be used to provide an electrical connection from one semiconductor chip to another semiconductor chip in a three-dimensional (3D) integration. Within a semiconductor chip, a conventional TSV structure may typically involve forming a trench, creating a liner over the walls of the trench, and subsequently filling the lined trench, for example, entirely with copper (Cu). Other TSV device structures such as optical TSVs may alternatively provide an optical connection between the semiconductor chips in the 3D integration. Thus, based on application, some semiconductor device may utilize both optical and electrical TSV structures.